On-board display system

ABSTRACT

A conventional display system carried on a railroad train has the problem that it cannot distribute image signal to the cars of the train when image information output means mounted in a lead car breaks down. 
     Accordingly, a display system to be carried on a railroad train according to the invention includes: first image information output means provided in a given car in a train of a plurality of connected cars, for outputting first image information; second image information output means provided in a given car of said train, for outputting second image information; and display means provided in a given car of said train, for switchably displaying said first image information transmitted from said first image information output means and said second image information transmitted from said second image information output means.

This application is the national phase under 35 U.S.C. §371 of PCTInternational Application No. PCT/JP00/09318 which has an Internationalfiling date of Dec. 27, 2000, which designated the United States ofAmerica.

TECHNICAL FIELD

The present invention relates to a display system that is carried on arailroad train to provide passengers in the passenger cars with variousinformation through images.

BACKGROUND ART

FIG. 11 shows a conventional display system mounted on a railroad train.In the figure, the reference characters 1 and 2 respectively denotefirst and second lead cars disposed at both ends of the train and 3denotes intermediate cars coupled between the lead cars 1 and 2. Thelead cars 1 and 2 are equipped with a driver's cab and train drivingmeans, though not shown in the figure. The reference character 4 adenotes an image information output means mounted in the first lead car1; 5 a denotes a termination means mounted in the second lead car 2; 6 adenotes an image information transmission path which has its one endconnected to the image information output means 4 a, passes through theintermediate cars 3, and is terminated at its other end by thetermination means 5 a; 7 a denotes branch means provided in the firstlead car 1, the intermediate cars 3, and the second lead car 2 to branchthe image information transmission path 6 a; and 8 denotes image displaymeans provided in the passenger section on each car and connected to theimage information transmission path 6 a branched by the branch means 7a.

Its operation is now described. An image signal outputted from the imageinformation output means 4 a is distributed to the individual cars 1 to3 through the image information transmission path 6 a. In each car, thebranch means 7 a extracts the image signal from the image informationtransmission path 6 a and gives it as input to the image display means 8to cause it to display the image.

The conventional display system carried on the train is constructed asshown above. However, it has the problem that the image signal cannot bedistributed to the individual cars when the image information outputmeans carried on the first lead car breaks down. Particularly, when theimage information output means breaks down by an accident such asderailment, fire, etc., it cannot provide passengers with evacuationinformation through image on the display means.

Furthermore, when a train of connected cars is separated during itsjourney into two trains bound for different destinations, for example,the train in which the image information output means is absent, i.e.the train containing the second lead car, cannot distribute imageinformation.

The present invention has been made to solve the problems shown above,and an object of the invention is to obtain a display system carried ona railroad train which is less likely to get into conditions in which itcannot distribute image information to the cars. Another object is toobtain a display system carried on a train which, even when one train ofconnected cars is separated into two trains, can distribute imageinformation in both trains of cars.

DISCLOSURE OF THE INVENTION

According to the present invention, a display system to be carried on arailroad train includes: first image information output means providedin a given car in a train of a plurality of connected cars, foroutputting first image information; second image information outputmeans provided in a given car of said train, for outputting second imageinformation; and display means provided in a given car of said train,for switchably displaying said first image information transmitted fromsaid first image information output means and said second imageinformation transmitted from said second image information output means,so that said display means can display image even when one of the firstand second image information output means has broken down.

Further, according to the invention, in the display system carried on arailroad train, said first image information output means and saidsecond image information output means are provided in different cars ofsaid train, which reduces the possibility that both the first and secondimage information output means break down at nearly the same time.

Further, according to the invention, in the display system carried on arailroad train, said first image information output means and saidsecond image information output means output image information forevacuating passengers, so that the safety of passengers can be ensured.

Further, according to the invention, in the display system carried on arailroad train, at least one of said first image information outputmeans and said second image information output means is a hard disk oran optical disk which are susceptible to faults due to vibrations, inwhich case it is very effective to reduce the possibility that both thefirst and second image information output means break down at nearly thesame time.

Further, according to the invention, in the display system carried on arailroad train, said display means includes first display means providedin a given car, for switchably displaying said first image informationand said second image information, and second display means provided ina car different from said car, for switchably displaying said firstimage information and said second image information, so that the trainof cars can be separated into two trains in such a way that each trainincludes at least one display means so that both trains can distributeimage information.

Further, according to the invention, in the display system carried on arailroad train, said first and second image information output means areprovided in cars equipped with driving means and disposed at both endsof said train, so that the train of cars can be separated into twotrains in such a way that both trains include image information outputmeans.

Further, according to the invention, the display system carried on arailroad train includes: first termination means provided in the car inwhich said second image information output means is provided; secondtermination means provided in the car in which said first imageinformation output means is provided; a first image informationtransmission path having its one end connected to said first imageinformation output means and its other end connected to said firsttermination means; a second image information transmission path havingits one end connected to said second image information output means andits other end connected to said second termination means; first branchmeans for extracting from said first image information transmission pathsaid first image information outputted from said first image informationoutput means and outputting said first image information to said displaymeans; and second branch means for extracting from said second imageinformation transmission path said second image information outputtedfrom said second image information output means and outputting saidsecond image information to said display means, which structure lessensthe restriction of the management of the cars.

Further, according to the invention, the display system carried on arailroad train includes: first termination means provided in the car inwhich said second image information output means is provided; an imageinformation transmission path having its one end connected to said firstimage information output means and its other end connected to said firsttermination means; second termination means provided in a car coupledbetween the car in which said first image information output means isprovided and the car in which said second image information output meansis provided; and switching means provided in said car in which saidsecond termination means is provided, for switchably connecting saidimage information transmission path to said first termination means andto said second termination means, whereby the image informationtransmission path can be terminated even when the train of cars has beenseparated into two trains, making it possible to distribute images ofgood quality.

Further, according to the invention, the display system carried on arailroad train includes: means for detecting that a car coupled to saidcar in which said second termination means is provided has beenseparated therefrom; and control means for controlling the switching bysaid switching means in accordance with a result of the detection,whereby the terminating resistors can be switched automatically when thecars are separated.

Further, according to the invention, the display system carried on arailroad train includes image information detecting means for detectinga halt of transmission of said first image information, wherein whensaid image information detecting means detects a halt of transmission ofsaid first image information, said display means switches its displayfrom said first image information to said second image information, andthus the images displayed by the display means can be switchedautomatically.

Further, according to the invention, the display system carried on arailroad train includes: fault detecting means for detecting a fault ofsaid first image information output means; and control means for, whensaid fault detecting means detects a fault of said first imageinformation output means, controlling said display means to switch thedisplay of said display means from said first image information to saidsecond image information, and thus the image displayed on the displaymeans can be switched automatically.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic structural diagram that illustrates a displaysystem carried on a train according to a first preferred embodiment.

FIG. 2 is a schematic structural diagram that illustrates a displaysystem carried on a train according to a second preferred embodiment.

FIG. 3 is a schematic structural diagram that illustrates a displaysystem carried on a train according to a third preferred embodiment.

FIG. 4 is an explanation diagram that illustrates a channel switchingmethod according to a fourth preferred embodiment.

FIG. 5 is a schematic structural diagram that illustrates a channelswitching method according to a fifth preferred embodiment.

FIG. 6 is a schematic structural diagram that illustrates a displaysystem carried on a train according to a sixth preferred embodiment.

FIG. 7 is a schematic structural diagram that illustrates the train ofFIG. 6 that has been separated into two.

FIG. 8 is a schematic structural diagram that illustrates anotherdisplay system carried on a train according to the sixth preferredembodiment.

FIG. 9 is a schematic structural diagram that illustrates a displaysystem carried on a train according to a seventh preferred embodiment.

FIG. 10 is a schematic structural diagram that illustrates the trainshown in FIG. 9 that has been separated.

FIG. 11 is a schematic structural diagram that illustrates aconventional display system carried on a train.

BEST MODE FOR CARRYING OUT THE INVENTION

First Preferred Embodiment

According to a first preferred embodiment, a display system to becarried on a railroad train has two sets of image information outputmeans and each display means receives image information from both of theimage information output means.

FIG. 1 is a schematic structural diagram that illustrates a displaysystem carried on a train according to a first preferred embodiment. Inthe diagram, the parts same as or corresponding to those in theconventional system are shown at the same reference characters and notdescribed again here. In FIG. 1, 4 a denotes a first image informationoutput means mounted in the lead car 1 to output a first image signaland 4 b denotes a second image information output means also mounted inthe lead car 1 to output a second image signal. The first imageinformation output means 4 a modulates the first image signal andoutputs it onto a first channel and the second image information outputmeans 4 b modulates the second image signal and outputs it onto a secondchannel different from the first channel. The reference character 9denotes synthesizing means for mixing the first channel and the secondchannel and provides output onto the image information transmission path6 a.

Its operation is now described. The first image signal outputted fromthe first image information output means 4 a and the second image signaloutputted from the second image information output means 4 b arepropagated on the image information transmission path 6 a anddistributed to the individual carts 1 to 3. In each car, the branchmeans 7 a extracts the first and second image signals from the imageinformation transmission path 6 a and provides them as input to theimage display means 8. The image display means 8 demodulates at leastone of the incoming first and second signals and displays the image.

As shown above, the display system of the first preferred embodiment hasa plurality of image information output means and each display meansreceives image information from the plurality of image informationoutput means, so that even if any of the image information output meansbreaks down, another image information output means can distribute imageinformation; therefore the distribution of image information to thedisplay means is not likely to be disabled.

A coaxial cable can be used as the image information transmission path 6a. The image information contained in the first image signal and theimage information contained in the second image signal may be the sameor different. The image display means 8 may demodulate and display oneof the first and second image signals or may demodulate and display bothsignals.

Second Preferred Embodiment

In the first preferred embodiment, the two sets of image informationoutput means are mounted in the same car. However, since the two imageinformation output means are therefore placed in similar environments(vibrations etc.), they may break down at nearly the same time.Furthermore, when one train of cars is separated into two trains, thetrain having no image information output means cannot distribute imageinformation. Accordingly, in a second preferred embodiment, the displaysystem carried on the train has two sets of image information outputmeans separately disposed in different cars.

FIG. 2 is a schematic structural diagram that illustrates a train-bornedisplay system of the second preferred embodiment. In the figure theparts same as or corresponding to those of the conventional system andthe system of FIG. 1 are shown at the same reference characters and notdescribed again here. Now, the second image information output means 4 bshown in FIG. 1 is mounted in the second lead car 2. Further, in FIG. 2,6 b denotes an image information transmission path which has its one endconnected to the second image information output means 4 b, passesthrough the intermediate cars 3, and is connected at its other end tothe synthesizing means 9.

Its operation is now described. The first image signal outputted fromthe first image information output means 4 a is inputted to thesynthesizing means 9. The second image signal outputted from the secondimage information output means 4 b is inputted to the synthesizing means9 through the image information transmission path 6 b. The synthesizingmeans 9 outputs the incoming first and second image signals onto thefirst image information transmission path 6 a. In each car, the branchmeans 7 a extracts the first and second image signals from the imageinformation transmission path 6 a and inputs them to the image displaymeans 8. The image display means 8 demodulates at least one of theincoming first and second image signals and displays the image.

As shown above, in the train-borne display system of the secondpreferred embodiment, a plurality of image information output means areseparately disposed on different cars, which reduces the possibilitythat all image information output means will break down at the sametime, thus reducing the possibility that the distribution of imageinformation to the display means will be disabled.

The first and second image information output means may be constructedto be operated by the crew, or to automatically detect an accident suchas derailment or fire, so as to output image information for urging thepassengers to evacuate. In this case, the second preferred embodiment isvery effective in ensuring the safety of passengers since the two setsof image information output means are not likely to break down at thesame time.

Furthermore, when one train of cars is separated into two trains, thecars can be separated in such a way that each train includes at leastone image information output means so that image information can bedistributed in both trains.

Third Preferred Embodiment

In the first preferred embodiment, the first lead car and the secondlead car are different in the structure of the display system carried onthe train. Accordingly the first lead car and the second lead car mustbe distinguished and differently handled, which restricts the managementof the cars. According to a third preferred embodiment, the first leadcar and the second lead car are constructed identically in the structureof the display system carried on the train.

FIG. 3 is a schematic structural diagram that illustrates a displaysystem carried on a train according to the third preferred embodiment.In the figure the parts same as or corresponding to those in theconventional system and the system of FIG. 1 are shown by the samereference characters and not described again here. The second imageinformation output means 4 b shown in FIG. 1 is mounted in the secondlead car 2 and both the first and second lead cars are equipped withrespective termination means.

In FIG. 3, 5 b denotes a second termination means provided in the firstlead car 1; 6 b denotes an image information transmission path that hasits one end connected to the second image information output means 4 b,passes through the intermediate cars 3, and has its other end connectedto the second termination means 5 b; 7 b denotes branch means providedin the first lead car 1, the intermediate cars 3, and the second leadcar 2 to branch the image information transmission path 6 b; and 9denotes synthesizing means connected to the image informationtransmission paths 6 a and 6 b branched by the branch means 7 a and 7 b,and for providing the first and second image signals on the transmissionpaths 6 a and 6 b as output to the image display means 8.

Its operation is now described. The first image signal outputted fromthe first image information output means 4 a is carried on the firstimage information transmission path 6 a and distributed to the cars 1 to3. In each car, the first branch means 7 a extracts the first imagesignal from the image information transmission path 6 a and outputs itto the synthesizing means 9. The second image signal outputted from thesecond image information output means 4 b is carried on the second imageinformation transmission path 6 b and distributed to the cars 1 to 3. Ineach car, the second branch means 7 b extracts the second image signalfrom the image information transmission path 6 b and outputs it to thesynthesizing means 9. The synthesizing means 9 outputs to the imagedisplay means 8 the first and second image signals coming from the firstand second branch means 7 a and 7 b. The image display means 8demodulates at least one of the input first and second image signals anddisplays the image.

As shown above, in the third preferred embodiment, the first lead carand the second lead car are the same in the structure of the displaysystem carried on the train, which lightens the restriction on themanagement of the cars.

That is to say, in the display system carried on the train shown in FIG.1, the first lead car is equipped with the image information outputmeans, while the second lead car is equipped with the termination means;thus the first and second lead cars are constructed in different waysand must be distinguished in organizing trains. On the other hand, thetrain-borne display system shown in FIG. 3 has an image informationoutput means, a first image information transmission path fortransmitting the output from that image information output means, asecond image information transmission path connected to another imageinformation output means provided in another car, and a terminationresistor for terminating the second image information transmission path;thus the first lead car and the second lead car have the same structureand the trains can be organized without the need to distinguish thefirst lead car and the second lead car.

Fourth Preferred Embodiment

The first to third preferred embodiments have described display systemscarried on the train in which each display means receives image signalsfrom a plurality of image information output means. A fourth preferredembodiment shows an example of a channel switching method in the imagedisplay means shown in the first to third preferred embodiments.

FIG. 4 is an explanation diagram that illustrates a channel switchingmethod of the fourth preferred embodiment. In the figure, the parts sameas or corresponding to those shown in FIGS. 1 to 3 are indicated by thesame reference characters are not described here. FIG. 4( a) is aschematic diagram illustrating the structure of the first and secondimage information output means 4 a and 4 b shown in FIGS. 1 to 3. In thefigure, 41 denotes image information recording means in which imageinformation is previously recorded, 42 denotes image information readingmeans for reading the image information from the image informationrecording means 41 and outputting the image information as an imagesignal, and 43 denotes modulating means for modulating the image signaloutputted from the image information reading means 42 and outputting theimage signal onto the first or second channel.

FIG. 4( b) is a schematic diagram illustrating the structure of theimage display means 8 shown in FIGS. 1 to 3. In the figure, 81 denotesdemodulating means for demodulating a given channel of the input signal,82 denotes image information detecting means for detecting whether thedemodulated signal contains image information, 83 denotes channel switchmeans for switching the channel to be demodulated by the demodulatingmeans 81 when the image information detecting means 82 has detectedabsence of image information, and 84 denotes a display screen fordisplaying the image contained in the demodulated signal.

Its operation is now described. First, the first and second imagesignals outputted from the first and second image information outputmeans 4 a and 4 b shown in FIGS. 1 to 3 are respectively carried on thefirst and second channels and provided to the image display means 8shown in FIG. 4( b). In the image display means 8, the demodulatingmeans 81 demodulates the first channel, for example, and the imagecontained in the first image signal is displayed on the display screen84.

Now, suppose that the first image information output means 4 a brokedown and the output of the first image signal halted. Then the imageinformation detecting means of FIG. 4( b) detects the absence of imageinformation in the output signal from the demodulating means 81 and thechannel switch means 83 receives the detected result and switches thetarget to be demodulated by the demodulating means 81 from the firstchannel to the second channel.

While the image information output means 4 a and 4 b have the imageinformation recording means 41 and the image information reading means42 in this example, they may contain radio wave receiving means (notshown) that receives an image signal sent through radio wave and outputsthe image signal to the modulating means 43, or may contain transmittedsignal receiving means (not shown) that receives an image signal sentthrough a transmission line provided in parallel with the railroad trackof the train and outputs the image signal to the modulating means 43.

Separately disposing the image information output means 4 a and 4 b indifferent cars is especially effective when the image informationrecording means 41 is one that is constructed to be mechanically drivenfor the reading of the recorded information, e.g. a hard disk head or anoptical disk pick-up, since such image information recording means 41are more likely to break down due to vibrations.

Fifth Preferred Embodiment

In the fourth preferred embodiment, the image display means detects theabsence of image information in the first channel and switches thedisplay channel from the first channel to the second channel. In a fifthpreferred embodiment, fault detecting means is provided to detect faultof the image information output means and the channel displayed by theimage display means is switched in accordance with the detected result.

FIG. 5 is a schematic structural diagram that illustrates a channelswitching method of the fifth preferred embodiment. In the figure, theparts same as or corresponding to those shown in FIGS. 1 to 4 areindicated by the same reference characters and not described again here.In the figure, 10 a denotes first fault detecting means for detectingfault of the image information output means 4 a and 10 b denotes secondfault detecting means for detecting fault of the image informationoutput means 4 b, where the first fault detecting means is provided inthe same car as the first image information output means 4 a and thesecond fault detecting means is provided in the same car as the secondimage output means. The results detected by the first and second faultdetecting means are transmitted to the channel switch means 85 in theimage display means 8 through the transmission paths 11 a and 11 b. Thechannel switch means 85 receives the detected results and switches thechannel to be demodulated by the demodulating means 81.

Its operation is now described. First, the first and second imagesignals outputted from the first and second image information outputmeans 4 a and 4 b are respectively carried on the first and secondchannels and inputted to the image display means 8. In the image displaymeans 8, the demodulating means 81 demodulates, for example, the firstchannel, and displays the image contained in the first image signal onthe display screen 84.

Now suppose that the first image information output means 4 a broke downand the output of the first image signal halted. Then the first faultdetecting means 10 a detects the fault of the first image informationoutput means 4 a and informs the channel switch means 85 of the detectedresult. On receiving the detected result, the channel switch means 85switches the target demodulated by the demodulating means 81 from thefirst channel to the second channel.

Sixth Preferred Embodiment

In the train-borne display systems according to the second and thirdpreferred embodiments, a plurality of image information output means areseparately disposed in different cars. Then, as already described, whenone train of connected cars is separated into two trains, the cars areseparated in such a way that each train contains at least one imageinformation output means so that the image information can bedistributed in both trains of cars. A sixth preferred embodiment showsan example of the train separating method.

FIG. 6 is a schematic structural diagram that illustrates a displaysystem carried on a train according to the sixth preferred embodiment.In the figure the parts same as or corresponding to those shown in FIG.3 are indicated by the same reference characters and not described againhere. In FIG. 6, 3 a and 3 b denote adjacent intermediate ears; 12 a and12 b denote switch means; and 13 a and 13 b denote termination means.The switch means 12 a and the termination means 13 a are mounted in theintermediate car 3 a and the switch means 12 b and the termination means13 b are mounted in the intermediate car 3 b. The switch means 12 aseparates the first image information transmission path 6 a into atransmission path 61 a connected to the first image information outputmeans 4 a and a transmission path 62 a connected to the terminationmeans 5 a and switchably connects the transmission path 61 a to thetransmission path 62 a and to the termination means 13 a. Similarly, theswitch means 12 b separates the second image information transmissionpath 6 b into a transmission path 62 b connected to the second imageinformation output means 4 b and a transmission path 61 b connected tothe termination means 5 b and switchably connects the transmission path61 b to the transmission path 62 b and to the termination means 13 b.

FIG. 7 illustrates the train of FIG. 6 that has been separated into twotrains. In FIG. 7 the parts same as or corresponding to those shown inFIG. 6 are indicated by the same reference characters and not describedhere again. In this figure the cars 3 a and 3 b are separated, with theswitch means 12 a connecting the transmission path 61 a and thetermination means 13 a and the switch means 12 b connecting thetransmission path 62 b and the termination means 13 b.

FIG. 7 illustrates the train of FIG. 6 that has been separated into twotrains. In FIG. 7 the parts same as or corresponding to those shown inFIG. 6 are indicated by the same reference characters and not describedhere again. In this figure the cars 3 a and 3 b are separated, with theswitch means 12 a connecting the transmission path 61 a and thetermination means 13 a and the switch means 13 b connecting thetransmission path 61 b and the termination means 13 b.

Its operation is now described. The first image signal outputted fromthe first image information output means 4 a is propagated on thetransmission path 61 a and distributed to the cars from the first leadcar 1 to the intermediate car 3 a. In the first lead car 1, theintermediate car 3 a, and the intermediate cars between them, the branchmeans 7 a provided on the transmission path 61 a extracts the firstimage signal from the transmission path 61 a and outputs the first imagesignal to the image display means 8 through the synthesizing means 9.

On the other hand, the second image signal outputted from the secondimage information output means 4 b is propagated on the transmissionpath 62 b and distributed to the cars from the second lead car 2 to theintermediate car 3 b. In the second lead car 2, the intermediate car 3b, and the intermediate cars 3 between them, the branch means 7 bprovided on the transmission path 62 b extracts the second image signalfrom the transmission path 62 b and outputs the second image signal tothe image display means 8 through the synthesizing means 9.

While the method for separating one train into two trains has beendescribed in the train-borne display system shown in FIG. 3, theseparation of one train into two can be similarly achieved by the methodshown in FIG. 8 in the train-borne display system shown in FIG. 2. InFIG. 8, the parts same as or corresponding to those shown in FIGS. 2 and7 are indicated by the same reference characters and not described againhere. In FIG. 8, in order to separate the train into two, thetransmission path 61 a is connected to the termination means 13 a andthe transmission path 62 a and the transmission path 62 b are connectedthrough the switches 15 a and 15 b.

As shown above, in the sixth preferred embodiment, termination means isprovided in a given car and switch means is provided in that given carto switchably connect the image information transmission path connectedto the image information output means to that termination means and totermination means provided in another car, so that the image informationtransmission path can be terminated even when the train is separatedinto two trains, making it possible to distribute image of good qualityto each car. Needless to say, the termination means and the switch meanscan be provided in all cars of the train.

Seventh Preferred Embodiment

In a seventh preferred embodiment, separation detecting means isprovided to detect the separation of cars and this detecting meanscontrols the switch means shown in the sixth preferred embodiment.

FIG. 9 is a schematic structural diagram that illustrates a displaysystem carried on a train according to a seventh preferred embodiment.In the figure, the parts same as or corresponding to those shown inFIGS. 6 and 7 are indicated by the same reference characters and notdescribed here again. In FIG. 9, 14 a and 14 b denote separationdetecting means for detecting the separation of cars. The separationdetecting means 14 a and 14 b send respective identification signals toeach other so that they can recognize that the intermediate car 3 a andthe intermediate car 3 b are coupled together.

FIG. 10 shows the train of FIG. 9 which has been separated apart. Atthis time, the separation detecting means 14 a detects the absence ofsignal reception from the separation detecting means 14 b and detectsthat the intermediate car 3 a and the intermediate car 3 b have beenseparated apart. Then it controls the switch means 12 a to connect thetransmission path 61 a to the termination means 13 a. In the same way,the separation detecting means 14 b detects the absence of signalreception from the separation detecting means 14 a and controls theswitch means 12 b to connect the transmission path 62 b to thetermination means 13 b.

As shown above, in the seventh preferred embodiment, the separationdetecting means for detecting the separation of cars controls theswitching to the termination means described in the sixth preferredembodiment. Needless to say, the same separation detecting means can beprovided in the train-borne display system shown in FIG. 8.

1. A display system to be carried on a railroad train, comprising: firstimage information output means provided in a given car in a train of aplurality of connected cars, for outputting first image information;second image information output means provided in a given car of saidtrain, for outputting second image information; display means providedin a given car of said train, for switchably displaying said first imageinformation transmitted from said first image information output meansand said second image information transmitted from said second imageinformation output means; first termination means provided in the car inwhich said second image information output means is provided; secondtermination means provided in the car in which said first imageinformation output means is provided; a first image informationtransmission path having its one end connected to said first imageinformation output means and its other end connected to said firsttermination means; a second image information transmission path havingits one end connected to said second image information output means andits other end connected to said second termination means; first branchmeans for extracting from said first image information transmission pathsaid first image information outputted from said first image informationoutput means and outputting said first image information to said displaymeans; and second branch means for extracting from said second imageinformation transmission path said second image information outputtedfrom said second image information output means and outputting saidsecond image information to said display means, wherein said first imageinformation output means and said second image information output meansare provided in different cars of said train.
 2. A display system to becarried on a railroad train, comprising: first image information outputmeans provided in a given car in a train of a plurality of connectedcars, for outputting first image information; second image informationoutput means provided in a given car of said train, for outputtingsecond image information; display means provided in a given car of saidtrain, for switchably displaying said first image informationtransmitted from said first image information output means and saidsecond image information transmitted from said second image informationoutput means; first termination means provided in the car in which saidsecond image information output means is provided; an image informationtransmission path having its one end connected to said first imageinformation output means and its other end connected to said firsttermination means; second termination means provided in a car coupledbetween the car in which said first image information output means isprovided and the car in which said second image information output meansis provided; and switching means provided in said car in which saidsecond termination means is provided, for switchably connecting saidimage information transmission path to said first termination means andto said second termination means, wherein said first image informationoutput means and said second image information output means are providedin different cars of said train.
 3. The display system carried on arailroad train according to claim 2, which comprises: means fordetecting that a car coupled to said car in which said secondtermination means is provided has been separated therefrom; and controlmeans for controlling the switching by said switching means inaccordance with a result of the detection.